This research proposal describes the qualifications and experience of the Division of Reproductive Endocrinology faculty and research team at the University of Texas Southwestern Medical Center at Dallas, the facilities, and patient population available to them for carrying out clinical protocols to be designed by the NICHD Reproductive Medicine Unit (RMU) Network. The UT Southwestern Division of Reproductive Endocrinology includes 6 clinicians, 4 of whom are board certified in Reproductive Endocrinology. Within the division is the Women's Research Center which includes 3 research nurses led by a research nurse coordinator with 20 years experience in protocol development and implementation are available for participation in RMU network protocols. This research team has successfully completed an extensive number of randomized trials, some of which were supported by NIH grant support as well as multi-center randomized trials supported by pharmaceutical companies. These investigations included infertility, andrology, endometriosis, uterine leiomyomata, androgen excess, contraception, and menopause. In order to develop an interdisciplinary approach to the study of reproductive disorders we have brought to the RMU network support of UT Southwestern's NIH General Clinical Research Center, Department of Urology, Psychiatry, Radiology, and Internal Medicine. A concept protocol is included which proposes to investigate pain relief in women suffering from endometriosis. This trial compares the effect of the medical treatment standard with gonadotropin releasing-hormone agonist versus continuous low-dose combined oral contraceptive pills. It is proposed that if continuous oral contraceptive pills are close in efficacy of relieving pain in women with endometriosis as are gonadotropin releasing hormone agonists, this mode of treatment would benefit a significant number of women wishing to save their reproductive organs for later reproduction. In summary, the reproductive endocrinology research team is experienced in multi- center clinical trials and is committed to collaborative participation consistent with the goals of the RMU network.